1. Field of the Invention
The present invention relates to a refrigerator, and, more particularly, to a refrigerator defined with freezing and refrigerating compartments, and equipped with independent evaporators respectively installed at the freezing and refrigerating compartments.
2. Description of the Related Art
Generally, a refrigerator includes a body defined with freezing and refrigerating compartments partitioned by an intermediate partition wall. Doors are hingably coupled to the refrigerator body in front of the freezing and refrigerating compartments to open and close the freezing and refrigerating compartments, respectively. An evaporator and a fan are arranged at an inner wall portion of the refrigerator body defining the freezing compartment, in order to generate cold air and to supply the generated cold air to the freezing compartment. Another evaporator and another fan are arranged at an inner wall portion of the refrigerator body defining the refrigerating compartment, in order to generate cold air and to supply the generated cold air to the refrigerating compartment. Thus, cold air is supplied into the freezing and refrigerating compartments in an independent fashion. Such a system is called an “independent cooling system”.
The reason why the system of cooling the freezing and refrigerating compartments in an independent fashion is used is that the target cooling temperature required in the refrigerating compartment is relatively higher than that required in the freezing compartment. In order to implement different cooling temperatures in the freezing and refrigerating compartments, respectively, the evaporators of the freezing and refrigerating compartments should have different evaporation temperatures, respectively. To this end, expansion (pressure reduction) of a refrigerant at an upstream side from each evaporator should be carried out in such a manner that the expansion degrees at respective upstream sides from the evaporators are different from each other. Accordingly, separate expansion devices are installed at respective upstream ends of the evaporators.
The independent cooling system may also implement independent cooling of a selected one of the freezing and refrigerating compartments. In order to independently cool a selected one of the freezing and refrigerating compartments, it is necessary to control a flow path of the refrigerant such that the refrigerant circulates through an associated one of the evaporators for the freezing and refrigerating compartments.
Different evaporation temperatures of the evaporators for the freezing and refrigerating compartments mean different refrigerant pressures of the evaporators. Such a refrigerant pressure difference causes the refrigerant to flow through one of the evaporators in a larger quantity, so that the refrigerant may not smoothly flow through the other evaporator when the refrigerant flow path is changed.